Downing Street has dismissed claims that it intervened to speed up NHS treatment for the wife of Singapore's former leader.

The denial followed media reports that the wife of Lee Kuan Yew was given treatment at the Royal London Hospital four and a half hours earlier than planned after medical staff were contacted by Downing Street.

Kwa Geok Choo, 82, was given a brain scan after suffering a stroke during a visit to London.

According to the Telegraph newspaper Lee was horrified to be told that his wife was "not as important" as three heart attack patients who were also awaiting treatment.

"Because of 10 Downing Street the CT scan was done at 3.30am," Lee said speaking after his return to Singapore. "And the blood clot could be seen clearly."

But Number 10 insisted it only became aware of the situation after the high profile patient had been treated.

"We did not become aware of her position until after the procedure had been carried out," said a spokesman for the prime minister.

Downing Street confirmed that a duty clerk had contacted the hospital to be briefed on the situation but denied seeking preferential treatment.

"As is appropriate a duty clerk simply phoned up to ascertain the position, not to put on any pressure. I think the health authority and the hospital have confirmed that," said the spokesman.

Downing Street added it would have been "entirely inappropriate" to have sought accelerated treatment for Choo.